Answers: Magnetic Fields and Inductors

Final results only. Come to class to ask how.

† Not in the OpenStax answer key; derived for these notes.

• 11.21(a) \(2.64\times 10^{-8}\,\mathrm{N}\), north; (b) the force is very small, so the effect is negligible← Problem
• 11.27(a) \(4.80\times 10^{-19}\,\mathrm{C}\); (b) 3; (c) charge comes in integer multiples of the electron charge, with no free charges smaller than this← Problem
• 11.35(a) into the page; (b) left; (c) out of the page← Problem
• 11.37(a) \(2.50\,\mathrm{N}\); (b) the power lines must be attached so that they are not moved by the force from Earth's magnetic field← Problem
• 11.53(a) \(4.4\times 10^{-8}\,\mathrm{s}\); (b) \(0.21\,\mathrm{m}\)← Problem
• 12.27At \(P_1\) the net field is zero; at \(P_2\), \(B=\dfrac{3\mu_0 I}{8\pi a}\) into the page← Problem
• 12.28At \(P_1\), \(B=\dfrac{\mu_0 I}{\pi a}\) into the page; at \(P_2\), \(B=\dfrac{\mu_0 I}{8\pi a}\) out of the page^†← Problem
• 12.55\(I = 0.0181\,\mathrm{A}\)← Problem
• 14.31(a) \(3.8\times 10^{-4}\,\mathrm{H}\); (b) \(3.8\times 10^{-4}\,\mathrm{H}\)← Problem
• 14.39\(\varepsilon = 480\pi\sin(120\pi t-\pi/2)\,\mathrm{V}\)← Problem
• 14.43(a) \(0.089\,\mathrm{H/m}\); (b) \(0.44\,\mathrm{V/m}\)← Problem